Do not concatenate numpy arrays.

* contrib/cone-vector.py: Import empty. Don't import concatenate.
(random_vector_on_spherical_cap): Build random vector without
concatenation.

1 files changed, 4 insertions, 3 deletions

diff --git a/contrib/cone-vector.py b/contrib/cone-vector.py
index 16d1dfa..6526817 100644
--- a/contrib/cone-vector.py
+++ b/contrib/cone-vector.py
@@ -16,7 +16,7 @@
 # along with this program.  If not, see
 # <https://www.gnu.org/licenses/>.
 
-from numpy import arcsin, concatenate, cos, dot, ones, sin, sqrt, tan, pi
+from numpy import arcsin, cos, dot, empty, ones, sin, sqrt, tan, pi
 from numpy.random import randn, random
 from numpy.linalg import norm
 from scipy.special import betainc, betaincinv, gamma
@@ -58,10 +58,11 @@ def rotate_from_nth_canonical (x, axis):
 def random_vector_on_spherical_cap (axis, maximum_planar_angle):
     dim = axis.size
     maximum_solid_angle_fraction = planar_angle2solid_angle_fraction(maximum_planar_angle, dim)
-    x = random_vector_on_sphere(dim - 1) \
+    x = empty(dim)
+    x[:-1] = random_vector_on_sphere(dim - 1) \
         * cos(maximum_planar_angle) \
         * tan(solid_angle_fraction2planar_angle(maximum_solid_angle_fraction*random(), dim))
-    x = concatenate([x, [cos(maximum_planar_angle)]])
+    x[-1] = cos(maximum_planar_angle)
     return rotate_from_nth_canonical(x / norm(x), axis)
 
 # Sample code exercising the above functions